Systemic inflammation response index correlates with survival and predicts oncological outcome of resected pancreatic cancer following neoadjuvant chemotherapy

Background: The Systemic Inflammation Response Index (SIRI) has been used to predict the prognosis of various cancers. This study examined SIRI as a prognostic factor in the neoadjuvant setting and determined whether it changing after chemotherapy is related to patient prognosis. Methods: Patients who underwent pancreatic surgery following neoadjuvant chemotherapy for pancreatic cancer were retrospectively analyzed. To establish the cut-off values, SIRIpre-neoadjuvant, SIRIpost-neoadjuvant, and SIRIquotient (SIRIpost-neoadjuvant/SIRIpre-neoadjuvant) were calculated and significant SIRI values were statistically determined to examine their effects on survival rate. Results: The study included 160 patients. Values of SIRIpost-neoadjuvant ≥ 0.8710 and SIRIquotient <0.9516 affected prognosis (hazard ratio [HR], 1.948; 95% confidence interval [CI], 1.210–3.135; ∗∗P = 0.006; HR, 1.548; 95% CI, 1.041–2.302; ∗∗P = 0.031). Disease-free survival differed significantly at values of SIRIpost-neoadjuvant < 0.8710 and SIRIpost-neoadjuvant ≥ 0.8710 (P = 0.0303). Overall survival differed significantly between SIRIquotient <0.9516 and SIRIquotient ≥0.9516 (P = 0.0368). Conclusions: SIRI can predict the survival of patients with pancreatic ductal adenocarcinoma after resection and neoadjuvant chemotherapy. Preoperative SIRI value was correlated with disease-free survival, while changes in SIRI values were correlated with overall survival.